Roller bit



April 23, 1935. H. STANCLIFF Thomas H. Sianclifl ROLLER BIT Fild March 20, 1933 IN VEN TOR.

ATTORNEY.

Patented Apr. 23, 1935 UNITED STATES PATENT OFFICE ROLLER BIT poration of Texas Application March 20,

16 Claims.

drill both hard and soft formations.

The conventional cross roller bit includes a pair of side roller cutters mounted on opposite sides of the cutter recess in the bit head and rotatable on spindles that incline upwardly and outwardly from the longitudinal axis of the head; and a plurality of cross roller cutters between said side roller cutters and rotatable on a cross roller cutter pin disposed at substantially a right angle to the longitudinal axis of the head. The

conventional cross roller cutters have thereon straight teeth and a plurality of themhave been placed on each side of the longitudinal axis of the head. 7

This invention provides a pair of spiral cutters to take the place of the straight tooth cutters heretofore used, to the end that a relatively small tooth area will be in contact with the formation momentarily to give a greater penetration speed, that the formation will be efficiently drilled by a scraping and shearing action, and that the teeth of the cutters will remain sharp for a greater length of time and will be self-cleaning in the formation.

Other objects will hereinafter appear.

The preferred embodiment of the invention is illustrated by the accompanying drawing, wherein Fig. 1 is a fragmentary sectional elevation of the bit; Fig. 2 a bottom plan view; and Fig. 3 a reduced partly sectional elevation taken at a right angle to Fig. 1.

In the drawing the bit head is indicated at I. It has in its lower end a cutter recess 2 defined by side roller cutter depending projections 3 and cross roller cutter depending projections 4. Within the cutter recess 2 is a bridge Shaving side roller cutter spindles 6 extending upwardly and outwardly in opposite directions andsupported by the bearing projections 3.

Extending diametrically across the recess 2 and through the bridge 5 and having its ends supported by the projections 4 is a cross roller cutter pin 1.

Rotatable upon the spindles 6 are side roller cutters 8 having substantially straight helically disposed teeth. Rotatable on the cross roller cutter pin 1 on opposite sides of the bridge 5 are a pair of cross roller cutters 9 and I0. Each of the cross roller cutters 9 and I0 is in main body form substantially frusto-conical and has its base end outermost. The cross roller cutters 9 and I0 have teeth 9a and Mia. disposed in rows in multiple spiral form upon the main body form, between which longitudinal grooves 9b and I 0b extend. In other words, the grooves intersect or cross the spiral rows at right angles thereto.

1933, Serial No. 661,669

The teeth of the side roller cutters may be arranged so that the cutting edges thereof are parallel with the axis of rotation of said cutters rather than helically disposed as shown, and substantial changes may be made in the construction of the cross roller cutters 9 and I 0, all within the scope of the following claims:

I claim:

1. A roller bit comprising a head; substantially cylindrical side roller cutters mounted on opposite sides of said head and rotatable on axes that are inclined upwardly and outwardly substantially from the longitudinal axis of said head; said side roller cutters having substantially straight helically disposed teeth; and a pair of multiple spiral frusto-conical cross roller cutters between said side roller cutters and rotatable on a substantially diametrical axis to traverse the area within the path of said side roller cutters; said cross roller cutters being arranged with their base ends outermost and having a plurality of grooves extending substantially from end to end between and at substantially a right angle to the teeth thereof disposed in rows in multiple spiral form.

2. A roller bit comprisinga head; substantially cylindrical side roller cutters mounted on opposite sides of said head and rotatable on axes that are inclined upwardly and outwardly substantially from the longitudinal axis of said head; said side roller cutters having substantially straight helically disposed teeth; and a pair of multiple spiral frusto-conical cross roller cutters between said side roller cutters and rotatable on a substantially diametrical axis to traverse the area within the path of said side roller cutters; said cross roller cutters being arranged with their base ends outermost and having a plurality of grooves extending substantially from end to end between the teeth thereof disposed in rows in multiple spiral form.

3. A roller bit comprising a head; substantially cylindrical side roller cutters mounted on opposite sides of said head and rotatable on axes that are inclined upwardly and outwardly substantially from the longitudinal axis of said head; said side roller cutters having substantially straight teeth; and a pair of multiple spiral frusto-conical cross roller cutters between said side roller,cutters and rotatable on a substantially diametrical axis to traverse the area within the path of said side roller cutters; said cross roller cutters being arranged with their base ends outermost and having a plurality of grooves extending substantially from end to end between the teeth thereof disposed in rowsin multiple spiral form.

4. A roller bit comprising a head; substantially cylindrical side roller cutters mounted on opposite sides of said head and rotatable on axes that are inclined upwardly and outwardly substantially from the longitudinal axis of said head; said side roller cutters having substantially straight teeth; and a pair of multiple spiral cross roller cutters between said side roller cutters and rotatable on a substantially diametrical axis to traverse the-area within the path of said side roller cutters; said cross roller cutters having a plurality of grooves extending substantially from end to end between the teeth thereof disposed in rows in multiple spiral form.

1 1 5. A roller bit comprising a head; side roller cutters mounted on opposite sides of said head on spindles that project upwardly and outwardly substantially from the longitudinal axis of said head; and a pair of multiple spiral cross roller cutters between said side roller cutters and rotatable on a substantially diametrical axis; said cross roller cutters having a plurality of grooves extending substantially from end to end between the teeth thereof disposed in rows in multiple spiral form.

6. A roller bit comprising a head; side roller cutters mounted on opposite sides of said head on spindles that project upwardly and outwardly substantially from the longitudinal axis of said head; and a pair of multiple spiral cross roller cutters between said side roller cutters and rotatable on a substantially diametrical axis.

7. A roller bit comprising a head, and a pair of multiple spiral substantially frusto-conical cutters, supported by said head so as to be rotatable about a transverse axis, said cutters being arranged with their base ends outermost and having a plurality of grooves extending from end to end and between the teeth thereof disposed in rows in multiple spiral form.

8. A roller bit comprising a head, and a pair'of multiple spiral substantially frusto-conical cutters supported by said head so as to be rotatable about a transverse axis, said cutters being arranged with their base ends outermost.

9. A multiple spiral substantially frusto-conical roller cutter having straight grooves extending substantially from end to end between and at substantially a right angle to the teeth thereof disposed in rows in multiple spiral form.

10. A multiple spiral substantially frusto-conical roller cutter having straight grooves extending substantially from end to end between the teeth thereof disposed in rows in multiple spiral form.

11. A multiple spiral roller cutter having straight grooves extending substantially from efid to end between the teeth thereof disposed in rows in multiple spiral form.

12. Aroller bit comprising a head; said head having a cutter recess in the bottom thereof; a bridge extending across said recess and having. upwardly and outwardly projecting side roller cutter spindles supported by opposite sides of said head; a cross roller cutter pin extending substantially diametrically across said recess and through and at substantially a right angle to said bridge, and supported at its opposite ends by said head; a substantially cylindrical side roller cutter on each of said spindles; said sid roller cutters having substantially straight hel1- cally disposed teeth; and a substantially frustoconical multiple spiral cross roller cuttezi on said cross roller cutter .pin on each side of said bridge and extending substantially from said bridge *to the opposite surface of said recess with its base end outermost; said cross roller substantially cylindrical side roller cutter on each of said spindles; said side roller cutters having substantially straight helically disposed teeth; and a substantially frusto-conical multiple spiral cross roller cutter on said .cross roller cutter pin on each side of said bridge and extending substantially from said bridge to the opposite surface of said recess with its base end outermost; said cross roller cutters having a plurality of grooves extending substantially from end to end between the teeth thereof disposed in rows in multiple spiral form.

14. A roller bit comprising a head; said head having a cutter recess in the bottom thereof; a bridge extending across said recess andhaving upwardly and outwardly projecting side roller cutter spindles supportedby opposite sides of said head; a cross roller cutter pin extending substantially diametrically across said recess at substantially a right angle to said bridge, and

supported at its opposite ends by said head; a

substantially cylindrical side roller cutter on each of said spindles; said side roller cutters having substantially straight teeth; and a substantially frusto-conical multiple spiral cross roller cutter on said cross roller cutter pin on each side of said bridge and extending substantially from said bridge to the opposite surface of said recess with its base end outermost.

15. A roller bit comprising a head; said head having a cutter recess in the bottom thereof; a bridge extending across said recess and having upwardly and outwardly projecting side roller cutter spindles supported by opposite sides of said head; a cross roller cutter pin extending substantially diametrically across said recess at substantially a right angle to said bridge, and supported at its opposite ends ofsaid head; a substantially cylindrical side roller cutter on each of said spindles; said side roller cutters having substantially straight teeth; and a multiple spiral cross roller cutter on said cross roller cutter pin on each side of said bridge and extending subcutter spindles supported by opposite sides of.

said head; a cross roller cutter pin extending subsubstantially diametrically across said recess at substantially a right angle to said bridge, and supported at its opposite ends by said head; a side roller cutter ,on each of said spindles; and a spiral cross roller cutter on said cross roller .cutter pin on each side of said bridge and extending substantially from said bridge to the op-' posite surface of said recess; 1

THOMAS H. STANCLIFE. 

